Parallelism: Parallelism happens when at least two units of work are executing simultaneously. It’s notable that you can support concurrency on a single processor system using appropriate scheduling, while parallelism requires multiple processors or systems.
Comments
The author states:
This is not correct. You can have concurrency on a single CPU with multiple threads.
Perhaps that's why the next line reads:
Parallelism: Parallelism happens when at least two units of work are executing simultaneously. It’s notable that you can support concurrency on a single processor system using appropriate scheduling, while parallelism requires multiple processors or systems.
But this sentence does not change the incorrect definition of concurrency in the previous line.
Yep: https://blog.golang.org/concurrency-is-not-parallelism
I also take issue with the idea that concurrency implies that each unit of work is continuously making progress.